Surface Area Volume Research Articles

Study on adsorption and purification materials for ethylene in cold storage

In view of the lack of systematic quantitative and comparative studies on the purification effect of ethylene adsorbent in cold storage, starting from the selection of purification materials, this paper analyzed the purification effect of different zeolite materials on ethylene through a small test chamber, and screened out the best zeolite adsorbents used in self-made purification device. Combined with characterization analysis, purification efficiency evaluation and adsorption capacity of zeolite material, the removal performance of ethylene was investigated. The results showed that the zeolite samples with rough and porous surface showed better adsorption performance for ethylene. The larger the specific surface area and total pore volume, the stronger the adsorption capacity to ethylene. In addition, the presence of Na elements and mesoporous increased the exchange capacity and pore volume, which also played a certain role in the ethylene adsorption process. Experimental result demonstrates that clean air volume (CADR) of ethylene is 232 m3/h, the ethylene removal rate at 30 min is 98.19%, and the purification energy efficiency is 1.39. At the same time, the adsorption capacity of the selected zeolite sample is 1380.5 μg/g by dynamic adsorption experiment, and the service life of the filter element of the self-made purification device is estimated to be 166 days. This study can provide a theoretical basis for ethylene purification in cold storage.

Genetic and environmental influences on structural brain development from childhood to adolescence: A longitudinal twin study on cortical thickness, surface area, and subcortical volume

The human brain undergoes structural development from childhood to adolescence, with specific regions in the sensorimotor, social, and affective networks continuing to grow into adulthood. While genetic and environmental factors contribute to individual differences in these brain trajectories, the extent remains understudied. Our longitudinal study, utilizing up to three biennial MRI scans (n=485), aimed to assess the genetic and environmental effects on brain structure (age 7) and development (ages 7–14) in these regions. Heritability estimates varied across brain regions, with all regions showing genetic influence (ranging from 18 % to 59 %) with additional shared environmental factors affecting the primary motor cortex (30 %), somatosensory cortex (35 %), DLPFC (5 %), TPJ (17 %), STS (17 %), precuneus (10 %), hippocampus (22 %), amygdala (5 %), and nucleus accumbens (10 %). Surface area was more genetically driven (38 %) than cortical thickness (14 %). Longitudinal brain changes were primarily driven by genetics (ranging from 1 % to 29 %), though shared environment factors (additionally) influenced the somatosensory cortex (11 %), DLPFC (7 %), cerebellum (28 %), TPJ (16 %), STS (20 %), and hippocampus (17 %). These findings highlight the importance of further investigating brain-behavior associations and the influence of enriched and deprived environments from childhood to adolescence. Ultimately, our study can provide insights for interventions aimed at supporting children's development.

Excellent adsorption and catalytic oxidation of toluene facilitated by metal-free nitrogen-doped mesoporous biochar

In this study, we synthesized a series of nitrogen-doped mesoporous biochar by a salt-templating method to assess the potential of our modified biochar for advanced remediation of toluene through either adsorption or catalytic oxidation. The principal findings indicated that the incorporation of nitrogen and the mesopore-forming agent significantly influenced the toluene removal performance by altering the physicochemical properties of the biochar. Notably, the sample synthesized at 900 °C (BUPZ-900) exhibited the exceptional toluene adsorption capacity, reaching 283.85 mg/g, due to its high surface area and mesopore volume. Advanced characterizations revealed that different nitrogen functionalities played distinct roles in the adsorption performance. The presence of graphitic nitrogen in BUPZ-900 enhanced toluene adsorption through π-π dispersion interactions. Conversely, BUPZ-600, boasting a high nitrogen content (8.66 at%) and a predominance of pyridinic-N (3.92 at%), exhibited the highest catalytic activity, despite its low adsorption capacity attributed to a smaller surface area. This heightened activity was attributed to the basicity of pyridinic-N, which acted as active sites, despite the material’s lower surface area. Our study highlights the promise of nitrogen-doped mesoporous biochar as an effective adsorbent or catalyst for advanced remediation of volatile organic compounds (VOCs), even in the absence of metal catalysts. This work emphasizes the critical role of synthesis temperature and nitrogen functionalization in optimizing biochar properties for environmental applications.

Tuning Textural Properties by Changing the Morphology of SBA-15 Mesoporous Materials.

Changing the morphology is an excellent option for altering the textural parameters of SBA-15 materials. This study provides a guide on how the properties of mesoporous structures behave according to their morphology and their contribution to thermal stability. The objective of this work was to synthesize different morphologies (spherical, hexagonal prisms, rice-like grains, rods, and fibers) of SBA-15 materials and evaluate the existing textural changes. The materials were synthesized by varying the temperature of the synthesis gel from 25 °C to 55 °C, with stirring at 300 or 500 rpm. The results of X-ray diffraction, Fourier transform infrared spectroscopy, N2 adsorption and desorption, and scanning electron microscopy were evaluated. Thermal stability tests were also conducted in an inert atmosphere. The materials were successfully synthesized, and it was observed that they all exhibited different characteristics, such as their ordering, interplanar distance, mesoporous parameter, specific surface area, micropore and mesopore volumes, external mesoporous area, and wall thickness. They also presented different thermal stabilities. The rice grain morphology had the highest specific surface area (908.8 cm2/g) and the best thermal stability, while the rod morphology had the best pore diameter (7.7 nm) and microporous volume (0.078 cm3/g).

An ultrasensitive electrochemical aptasensor based on zeolitic imidazolate framework-67 loading gold nanoparticles and horseradish peroxidase for detection of aflatoxin B1

Aflatoxin B1 (AFB1) is one of the most toxic mycotoxins and poses a high risk to human health. Highly sensitive and rapid detection is one of the most effective preventive measures to avoid potential hazards. Herein, an electrochemical aptasensor based on DNA nanotetrahedron and zeolitic imidazolate framework-67 loading gold nanoparticles, horseradish peroxidase, and aptamers was designed for the ultrasensitive detection of AFB1. The high specific surface area and large pore volume of zeolitic imidazolate framework-67 can increase the loading capacity and further improve the detection sensitivity of electrochemical aptasensors. DNA nanotetrahedron can enhance the capture ability of AFB1 with steady immobilization. The developed aptasensor showed good analytical performance for AFB1 detection, with a detection limit of 3.9 pg mL−1 and a wide linear range of 0.01–100 ng mL−1. The aptasensor detected AFB1 in corn samples with recovery rates ranging from 94.19%–105.77% and has potential for use in food safety monitoring.

Strychnos potatorum seeds derived magnetic graphene oxide nanocomposite for removal of nickel from wastewater: Adsorption performance, isotherm, kinetic and desorption behavior

In the present study investigates the adsorption of nickel ions by Strychnos potatorum seeds derived magnetic graphene oxide (SP-MGO). The fitness of the derived material was analyzed using BET and zeta seizer which proves the suitability of this adsorbent for adsorption process. The surface area, pore size and pore volume were obtained through BET analysis and the results were 51.798 (m2/g), 16.795 nm and 0.217 (cm3/g) respectively. And the size of the nanoparticle was measured using zeta seizer. For achieving maximum adsorption capacity, the following optimized conditions were; 60 min of contact time, under pH of 8, with 10 mg of SP-MGO dose, for the concentration of 10 mg/l, at the temperature of 35 °C. Freundlich isotherm (R2 =0.999) and pseudo second order (R2 =0.997) was well described the adsorption process. According to the isotherm model the adsorption of nickel ions occurs by multilayer of adsorption on heterogeneous surface of SP-MGO nanoadsorbent and also by chemisorption according to kinetic model. The Langmuir monolayer adsorption capacity (Q max) obtained by SP-MGO was 6.66 mg/g. The regeneration ability of SP-MGO was only reduced 17.1 % even after five cycles of adsorption runs. Overall, the SP-MGO can be a potential option for develop into a commercial adsorbent for industrial use to eliminate the pollutants from waste water.

Enhanced peroxymonosulfate activation for effective norfloxacin degradation by sepiolite-based FeCo layered double hydroxide composite

In this study, the FeCo layered double hydroxide/Sepiolite composite was successfully synthesized by a water bath approach which exhibited outstanding norfloxacin (NOR) degradation performance in presence of peroxymonosulfate (PMS). The reaction rate constant in the FeCo-LDH/Sepiolite/PMS system was 0.1644 min−1, which was around 1.78 times greater than that in the FeCo-LDH/PMS system. The introduction of the sepiolite carrier, which led to an increase in specific surface area and pore volume, was principally responsible for the considerable improvement in PMS activation efficiency. Moreover, the composite presented good stability and reusability. According to the results of the electron paramagnetic resonance (EPR) and quenching tests, the predominant reactive species in the FeCo-LDH/Sepiolite/PMS/NOR system were SO4•- and 1O2. Furthermore, possible NOR degradation pathways and catalytic mechanism were proposed. In summary, our research provised new ideas in the synthesis of promising mineral based PMS catalyst for wastewater treatment.

Catalytic transfer hydrogenation of α-angelica lactone over Nickel(II) modified UiO-66 metal organic framework under mild conditions

In the realm of biomass valorization, catalysts play a pivotal role, and UiO-66(Zr), a type of metal organic framework (MOF), emerges as a promising heterogeneous catalyst. This study focuses on incorporating Ni2+ into UiO-66(Zr) for application in catalytic transfer hydrogenation (CTH) of bio-derived α-angelica lactone (a-AL) to ɣ-valerolactone (GVL). The synthesis of UiO-66(Zr) occurs through a solvothermal process at 120 °C for 24 h. Ni(II) modification, achieved through wet impregnation with loadings of 2.5 and 5.0 wt%, results in no observable diffraction peaks associated with Ni particles in XRD analysis. FTIR analysis indicates significant shifts, suggesting deprotonation of the carboxylic moiety from the ligand and coordination with Zr4+ metal ion. Nitrogen sorption isotherms show a reduction in surface area and pore volume upon Ni(II) incorporation. FESEM analysis reveals particle agglomeration and increased size with Ni(II) introduction. EDX and HRTEM confirm the presence of 0.9 and 1.8 wt% Ni(II) on UiO-66(Zr). TG/DTA analysis affirms that Ni(II) does not affect the thermal stability of UiO-66(Zr). Ultimately, the introduction of Ni(II) enhances the catalytic performance of UiO-66(Zr), increasing the conversion and selectivity towards ɣ-valerolactone from 67 to 83.3 % and 71.6 % to 97.4 %, respectively, under mild reaction conditions.

Catalytic Dehydrogenation on Ultradisperse Sn-Promoted Ir Catalysts Supported on MgAl2O4 Prepared by Different Techniques

Ir and IrSn catalysts with different Sn contents (0.5, 0.7 and 0.9 wt%) were prepared using MgAl2O4 supports synthesized using two different techniques (the citrate–nitrate combustion and coprecipitation methods). Both supports, with a spinel structure, presented low acidity and good textural properties. However, the support prepared by coprecipitation had higher specific surface area and pore volume than the one prepared by combustion, which would favor the dispersion of the metals to be deposited. Likewise, during the preparation of the catalytic materials, a very good interaction was achieved between the metals and both supports, which was confirmed by the presence of sub-nanometer atomic clusters in the mono- and bimetallic catalysts. Regarding the catalytic properties, while the monometallic Ir/MgAl2O4 samples lead to a very low conversion of n-butane and a selectivity towards hydrogenolysis products, the addition of Sn to Ir increases the conversion, decreases hydrogenolysis and therefore sharply increases the selectivity towards the different butenes. Catalysts with higher Sn loadings present better catalytic behavior. One of the roles of the Sn promoter would be to geometrically modify the Ir clusters, drastically decreasing the hydrogenolytic activity. This effect, added to the strong electronic modification of the Ir sites by the action of Sn, with probable Ir-Sn alloy formation, is responsible for the high catalytic performance of these bimetallic catalysts.

Genetic evidence for the causal relationships between migraine, dementia, and longitudinal brain atrophy

BackgroundMigraine is a neurological disease with a significant genetic component and is characterized by recurrent and prolonged episodes of headache. Previous epidemiological studies have reported a higher risk of dementia in migraine patients. Neuroimaging studies have also shown structural brain atrophy in regions that are common to migraine and dementia. However, these studies are observational and cannot establish causality. The present study aims to explore the genetic causal relationship between migraine and dementia, as well as the mediation roles of brain structural changes in this association using Mendelian randomization (MR).MethodsWe collected the genome-wide association study (GWAS) summary statistics of migraine and its two subtypes, as well as four common types of dementia, including Alzheimer’s disease (AD), vascular dementia, frontotemporal dementia, and Lewy body dementia. In addition, we collected the GWAS summary statistics of seven longitudinal brain measures that characterize brain structural alterations with age. Using these GWAS, we performed Two-sample MR analyses to investigate the causal effects of migraine and its two subtypes on dementia and brain structural changes. To explore the possible mediation of brain structural changes between migraine and dementia, we conducted a two-step MR mediation analysis.ResultsThe MR analysis demonstrated a significant association between genetically predicted migraine and an increased risk of AD (OR = 1.097, 95% CI = [1.040, 1.158], p = 7.03 × 10− 4). Moreover, migraine significantly accelerated annual atrophy of the total cortical surface area (-65.588 cm2 per year, 95% CI = [-103.112, -28.064], p = 6.13 × 10− 4) and thalamic volume (-9.507 cm3 per year, 95% CI = [-15.512, -3.502], p = 1.91 × 10− 3). The migraine without aura (MO) subtype increased the risk of AD (OR = 1.091, 95% CI = [1.059, 1.123], p = 6.95 × 10− 9) and accelerated annual atrophy of the total cortical surface area (-31.401 cm2 per year, 95% CI = [-43.990, -18.811], p = 1.02 × 10− 6). The two-step MR mediation analysis revealed that thalamic atrophy partly mediated the causal effect of migraine on AD, accounting for 28.2% of the total effect.DiscussionThis comprehensive MR study provided genetic evidence for the causal effect of migraine on AD and identified longitudinal thalamic atrophy as a potential mediator in this association. These findings may inform brain intervention targets to prevent AD risk in migraine patients.

High-pressure gas adsorption on activated carbons from pomegranate peels biochar: A promising approach for biogas purification

Biogas is a promising bioenergy source and its composition is based on methane (55–70% vol) but contains impurities such as CO2 (30–45% vol). Various technologies are available to purify biogas and produce biomethane that can be injected into the existing natural gas network. In this work, the effectiveness of activated carbons (ACs) obtained by chemical activation from industrial food waste for CO2 removal by adsorption was investigated. ACs with better textural development were obtained at higher activation temperature and dose of the activating agent (BET surface area and total pore volume up to 1446 m2/g and 0.589 cm3/g, respectively). The adsorbents exhibited a microporous character (micropore volume up to 0.472 cm3/g). The ACs were tested in high-pressure gas adsorption tests (CO2, CH4 and H2 up to 3, 8 and 4 MPa, respectively). All of them showed high, medium and low selectivity against for the adsorption of CO2, CH4 and H2, respectively, although with different efficiencies. The adsorbent obtained under the most aggressive activation conditions (900 °C, 1:1 wt ratio) showed the greatest textural development and the maximum adsorption capacity for CO2 (at 3 MPa) and CH4 (at 8 MPa) (495 mgCO2/g and 126 mgCH4/g). Despite the porosity of the materials, all showed a very low affinity for hydrogen adsorption at 4 MPa (up to 3.71 mgH2/g). Taking the above into account, these activated carbons could be used in the purification of biogas and in the separation of CO2/H2 mixtures to produce pure H2 and obtain hydrogen-free CO2 for capture and storage.

Symbiotic defect-reinforced bimetallic MOF-derived fiber components for solar-assisted atmospheric water collection

Conversion of atmospheric water to sustainable and clean freshwater resources through MOF-based adsorbent has great potential for the renewable environmental industry. However, its daily water production is hampered by susceptibility to agglomeration, slow water evaporation efficiency, and limited water-harvesting capacity. Herein, a solar-assisted bimetallic MOF (BMOF)-derived fiber component that surmounts these limitations and exhibits both optimized water-collect capacity and short adsorption-desorption period is proposed. The proposed strategy involves utilizing bottom-up interface-induced assembly between carboxylated multi-walled carbon nanotube and hygroscopic BMOF on a multi-ply glass fiber support. The designed BMOF (MIL-100(Fe,Al)-3) skeleton constructed using bimetallic-node defect engineering exhibits a high specific surface area (1,535.28 m2/g) and pore volume (0.76 cm3/g), thereby surpassing the parent MOFs and other reported MOFs in capturing moisture. Benefiting from the hierarchical structure of fiber rods and the solar-driven self-heating interface of photothermal layer, the customized BMOF crystals realize efficient loading and optimized water adsorption-desorption kinetics. As a result, the resultant fiber components achieve six adsorption-desorption cycles per day and an impressive water collection of 1.45 g/g/day under medium-high humidity outdoor conditions. Therefore, this work will provide new ideas for optimizing the daily yield of atmospheric water harvesting techniques.

An investigation for optical, photocatalytic, photoluminescence and dielectric properties of Cd0.40Ni0.60ZnO2 annealed nanocomposites

We report here the optical, photoluminescence (PL), and dielectric properties of Cd0.40Ni0.60ZnO2 nanocomposites annealed between 200 and 600oC. An increase in annealing temperature (Tann) up to 600oC correlates with a gradual increase in the crystallite and particle sizes. The surface area, pore radius, and pore volume are increased as Tann increases from 200oC to 300oC, and then decreased, but still higher than of 200oC. Similar behaviors were obtained for the absorbance carrier density, photocatlytic efficiency, degradation rate, PL intensity, dielectric constant, dielectric loss, ac conductivity, F-factor, series resistance, and electronic polarizability. While the energy gap, binding energy, impedance of grains and their boundaries, and effective capacitance show an opposite behavior. The relaxation times at the peak of dielectric parameters are between 11.54 and 159.24ns and between 35.23 and 24273.73ns, respectively. The Cole-Cole plot shows a single semicircle at Tann < 400oC and two successive semicircles at Tann> 500oC. The energy of PL of visible emissions is independent on the chosen Tann. These findings indicated that the nanocomposite annealed at 300oC can be used for water purification, telecommunications, solar cells, supercapacitor, and white light-emitting diodes (LEDs).

Efficient adsorptive removal of 2,4-dichlorophenoxyacetic acid (2,4-D) using biomass derived magnetic activated carbon nanocomposite in synthetic and simulated agricultural runoff water

This study focused on evaluating the efficacy of a magnetic activated carbon material (CPAC@Fe3O4) derived from pods of copper pod tree in adsorbing the toxic herbicide, 2,4- (2,4-D) from aqueous solutions. The synthesized CPAC@Fe3O4 adsorbent, underwent various characterization techniques. FESEM images indicated a rough surface, incorporating iron oxide nanoparticles, while EDS analysis confirmed the presence of elements like Fe, O, and C. Notably, the CPAC@Fe3O4 exhibited high surface area (749.10 m2/g) and pore volume (0.5351 cm³/g), confirming its mesoporous nature. XRD investigations identified distinct signals associated with graphitic carbon and magnetite nanoparticles, while VSM analysis verified its magnetic properties with a high magnetic saturation value (2.72 emu/g). The adsorption process was exothermic, with a decrease in adsorption capacity at higher temperatures. Freundlich isotherm provided the best fit for the adsorption, and the pseudo-second-order equation effectively described the kinetics. Remarkably, the maximum adsorption capacity ranged from 246.43 to 261.03 mg/g, surpassing previously reported values. The ΔH° value (−8.67 kJ/mol) suggested a physisorption mechanism, and the negative ΔG° values established the spontaneous nature. Furthermore, the synthesized adsorbent demonstrated exceptional reusability, allowing for up to five cycles of adsorption-desorption operations. When applied to simulated agricultural runoff, CPAC@Fe3O4 showcased a significant adsorption capacity of 160.71 mg/g for 50 mg/L 2,4-D, using a 0.2 g/L dosage at pH 2. This study showcased the transformation of copper pod biomass into a valuable magnetic nanoadsorbent capable of efficiently eliminating the noxious 2,4-D pollutant from aqueous environments.

Atrazine degradation through a heterogeneous dual-effect process using Fe–TiO2-allophane catalysts under sunlight

This study investigated the novel application of Fe–TiO2-allophane catalysts with 6.0 % w/w of iron oxide and two TiO2 proportions (10 % and 30 % w/w) for degrading atrazine (ATZ) using the heterogeneous dual-effect (HDE) process under sunlight. Comparative analyses with Fe-allophane and TiO2-allophane catalysts were conducted in both photocatalysis (PC) and HDE processes. FTIR spectra reveal the unique hydrous feldspathoids structure of allophane, showing evidence of new bond formation between Si–O groups of allophane clays and iron hydroxyl species, as well as Si–O–Ti bonds that intensified with higher TiO2 content. The catalysts exhibited an anatase structure. In Fe–TiO2-allophane catalysts, iron oxide was incorporated through the substitution of Ti4+ by Fe3+ in the anatase crystal lattice and precipitation on the surface of allophane clays, forming small iron oxide particles. Allophane clays reduced the agglomeration and particle size of TiO2, resulting in an enhanced specific surface area and pore volume for all catalysts. Iron oxide incorporation decreased the band gap, broadening the photoresponse to visible light. In the PC process, TiO2-allophane achieves 90 % ATZ degradation, attributed to radical species from the UV component of sunlight. In the HDE process, Fe–TiO2-allophane catalysts exhibit synergistic effects, particularly with 30 % w/w TiO2, achieving 100 % ATZ degradation and 85 % COD removal, with shorter reaction time as TiO2 percentage increased. The HDE process was performed under less acidic conditions, achieving complete ATZ degradation after 6 h without iron leaching. Consequently, Fe–TiO2-allophane catalysts are proposed as a promising alternative for degrading emerging pollutants under environmentally friendly conditions.

PMMA microspheres-embedded Ti3C2Tx MXene heterophotocatalysts synergistically working for multiple dye degradation

We developed a novel MXene/polymer hybrid material for enhanced photodegradation of multiple organic dyes. Specifically, uniform-sized PMMA microspheres and multilayer Ti3C2Tx MXene were integrated through a facile solution process to form PMMA/Ti3C2Tx composites. The hybridization of the two components significantly increased the specific surface area and pore volume. An optimized composite showed high photocatalytic activity, demonstrating 93 and 98 % degradation efficiencies for orange G (OG) and rhodamine B (RhB) in 60 min of light illumination. Furthermore, the composite revealed good recyclability without a significant performance drop even after four cycles. Moreover, the composite retained its high photocatalytic activity at various conditions, including elevated temperatures, a wide range of pH levels, and in tap water. These results manifest that the PMMA/Ti3C2Tx hetero-photocatalyst is well suited for use in wastewater treatment and environmental cleanup.

Synthesis of Mesoporous Silica from Palm Oil Boiler Ash (MS-POBA) with Addition of Methyl Ester Sulfonate as a Template for Free Fatty Acid Adsorption from Crude Palm Oil (CPO)

The synthesis of mesoporous material by utilizing palm oil boiler ash (POBA) waste as the silica source and methyl ester sulfonate (MES) surfactant as the template for a high-porosity was investigated for free fatty acids (FFA) adsorption. The research was initiated with silica extraction from POBA by sodium hydroxide addition through the sol-gel precipitation method. Silica modification was carried out with MES surfactant and 3-aminopropyltrimethoxysilane (APTMS) as the co-structure-directing agent (CSDA) in different calcination temperatures. Mesoporous silica-POBA (MS-POBA) free template had a surface area, pore diameter, and pore volume (41.033 m2/g, 4.180 nm, and 0.250 cm3/g) lower than MS-POBA with the template (71.0147 m2/g, 7.923 nm, and 0.524 cm3/g). The ability of MS-POBA to adsorb FFA reached its optimum conditions with an adsorption time of 20 min and an adsorbent dosage of 0.24 g. The FFA removal by MS-POBA with the template was found to have higher adsorption ability, which was 35.54%, compared to the MS-POBA free template of 26.68%. The high porosity of MS-POBA with a template makes the FFA adsorption capacity of this material higher than MS-POBA free template.

Effect of patient characteristics on aortic attenuation in iodinated contrast-enhanced Abdominopelvic CT: A retrospective study

IntroductionContrast Enhanced Computed Tomography (CECT) abdomen and pelvis is a common imaging procedure. Hospitals typically follow fixed protocols of contrast volume administration for triple-phase CECT abdomen and pelvis scans and have found that patients are either underdosed or overdosed with respect to their body habitus. The aim of the study was to correlate different patient characteristics such as Total body weight (TBW), Lean Body Mass (LBM), Body Mass Index (BMI), Body Surface Area (BSA) and Blood Volume (BV) with aortic enhancement in the arterial and portal venous phases for CECT Abdomen and pelvis. MethodsA total of 106 patients who underwent triple-phase CECT abdomen & pelvis were retrospectively studied. A circular region-of-interest (ROI) of 100 mm2 was positioned on descending aorta for unenhanced, arterial, and portal venous phases to measure the aortic enhancement in Hounsfield's units. Measure of contrast attenuation (ΔH) was calculated from the difference of CT values on unenhanced images and contrast images. Correlation analysis was performed to evaluate the relation of patient body characteristics with aortic enhancement. ResultsCorrelation analysis revealed that BMI exhibited the least correlation when compared to the other characteristics in both arterial (r = −0.3; p = 0.002) and portovenous phases (r = −0.35; p < 0.001) whereas TBW, LBW, BSA and BV reported moderate inverse correlations. BV was found to be the strongest of all characteristics under linear regression. ConclusionThe study supports the use of protocols that adjust contrast volume to either TBW, LBW, BSA, or BV for CT abdomen and pelvis scan. Implication of practiceThe right body parameter ensures optimal contrast enhancement, improving the visualization of anatomical structures and helps in adapting tailored contrast injection protocols.

Study on the mechanism of carbon nanotube-like carbon deposition in tar catalytic reforming over Ni-based catalysts

The use of Ni-based catalysts is a common method for eliminating tar through catalytic cracking. Carbon deposition is the main cause of deactivation in Ni/ZSM-5 catalysts, with filamentous MWCNTs being the primary form of carbon deposits. This study investigates the formation and evolution of CNTs during the catalytic process of biomass tar to explore the mechanism behind carbon deposition. The effect of the 9Ni/10MWCNTs/81ZSM-5 on toluene reforming was investigated through a vertical furnace. Gases produced by tar catalysis were evaluated through GC analysis. The physicochemical structure, properties and catalytic performance of the catalyst were also tested. TG analysis was used to assess the accumulation and oxidation reactivity of carbon on the catalyst surface. An analysis was conducted on the mechanism of carbon deposition during catalyst deactivation in tar catalysis. The results showed that the 9Ni/91ZSM-5 had a superior toluene conversion of 60.49%, but also experienced rapid and substantial carbon deposition up to 52.69%. Carbon is mainly deposited as curved filaments on both the surface and pore channels of the catalyst. In some cases, tip growth occurs where both carbon deposition and Ni coexist. Furthermore, specific surface area and micropore volume are reduced to varying degrees due to carbon deposition. With the time increased, the amount of carbon deposited on the catalyst surface increased to 62.81%, which gradually approached saturation, and the overall performance of the catalyst was stabilized. This situation causes toluene molecules to detach from the active sites within the catalyst, hindering gas release, which leads to reduced catalytic activity and further carbon deposition. It provides both a basis for the development of new catalysts and an economically feasible solution for practical tar reduction and removal.

Improving Adsorption Efficiency of Recycled Activated Carbon from Household Water Purifiers through Sonication

Objectives:This study evaluated the potential of recycled activated carbon from household water purifiers as an adsorbent for removing methylene blue. It aimed to achieve resource recycling and dyeing wastewater treatment through the sonication modification of recycled activated carbon.Methods:After sieving recycled activated carbon from water purifiers to a particle size of 75-150μm, the material, in this paper referred to as PCB-S, was processed using sonication to enhance its adsorption capacity. The characteristics of PCB-S were analyzed using SEM, XRD and BET analysis. To evaluate its efficacy, adsorption experiments were carried out varying the following parameters: PCB-S dosage (0.05-0.6gL-1), pH (2.0-10.0), initial concentration of methylene blue (100mgL-1), reaction time (1440 min), and temperature (298 K). The data from these experiments were analyzed using first and second-order kinetic models to understand the reaction kinetics, and the adsorption efficiency was further compared using Langmuir and Freundlich isotherm models. Finally, the thermodynamic properties of the adsorption process between PCB-S and methylene blue were studied to determine its endothermic nature and spontaneity.Results and Discussion:The analysis of the surface characteristics of PCB and PCB-S revealed that sonication significantly altered the pore structure of the activated carbon, leading to increases in both the specific surface area and pore volume. XRD analysis, indicated that sonication had no impact on the crystalline or amorphous structure of the activated carbon. PCB-S demonstrated superior porosity and adsorption capabilities compared to PCB. With a dosage of 0.6gL-1, PCB-S was able to remove 65% of methylene blue from the solution. The adsorption kinetics were best described by a pseudo-second-order kinetic model, with the Langmuir adsorption isotherm fitting the data most accurately. The Gibbs free energy (-1.90~-1.32kJ mol-1) and enthalpy change (7.44 kJ mol-1) confirmed that the adsorption reaction was endothermic.Conclusion:This study confirmed that recycled activated carbon from water purifiers exhibits excellent effectiveness as a dye removal adsorbent when subjected to sonication treatment. Therefore, the possibility of utilizing recycled household water purifier filters as adsorbents is expected to contribute to reducing waste disposal costs by promoting resource recycling.